Monday, May 4, 2009
11-20
Effect of biodiesel-derived raw glycerol on 1,3-propanediol production by different microorganisms
Chuloo Moon1, Seung Wook Kim2, Byoung-In Sang1, and Youngsoon Um1. (1) Center for Environmental Technology Research, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Seongbuk-gu, Seoul, South Korea, (2) Department of Chemical and Biological Engineering, Korea University, 1, Anam-dong, Sungbuk-ku, Seoul, South Korea
There is a great advantage to use biodiesel-derived raw glycerol for the various chemical productions from economical and environmental standpoints. In this study, the production of 1,3-propanediol (1,3 PD) was investigated with pure glycerol, raw glycerol, and acid-pretreated raw glycerol using different 1,3 PD-producing microorganisms. There was no inhibitory effect of raw glycerol on 1,3 PD production when Klebsiella pneumoniae DSM2026 and K. pneumoniae DSM4799 were tested. In contrast, the growth and 1,3 PD production of Clostridium butyricum DSM15410, C. butyricum DSM2477, C. butyricum DSM2478, and C. pasteurianum DSM525 was inhibited in the presence of raw glycerol. A simple acid treatment of raw glycerol was performed to remove impurities in raw glycerol, and the pre-treated glycerol was tested if it could support cell growth and 1,3 PD production. Using the pretreated raw glycerol, the production of 1,3-PD by C. butyricum DSM 2477, C. butyricum DSM 2478, and C. pasteurianum DSM 525 was similar to that with pure glycerol, whereas there was about 50% inhibition on 1,3 PD production with C. butyricum DSM 15410. In conclusion, K. pneumoniae DSM2026 and K. pneumoniae DSM4799 successfully converted raw glycerol to 1,3 PD without any inhibition effect. Although the tested clostridia strains in this study did not grow well with raw glycerol, a simple acid treatment of raw glycerol was effective to remove impurities and, consequently, support the growth of the clostridia strains. Identification of impurities causing the growth inhibition in raw glycerol has been also investigated in detail for each microorganism.